Heo Young-Saeng (Hangul: 허영생; Hanja: 許永生; born: November 3, 1986) is a South Korean entertainer and the main vocalist of boyband SS501. He's also the leader of 'Double S 301'.
In 2010, Heo left DSP Media, who managed him as part of SS501, and moved to B2M Entertainment, with bandmate Kim Kyu-Jong, to pursue his solo career. His debut album as a soloist entitled Let It Go was released in May 2011. He then released several albums more in Korea and Japan, with the hit tracks "Crying", "The Art of Seduction", "Weak Child", and "1.2.3", among others. In 2012, Heo played his first acting role in KBS2's sitcom I Need A Fairy.